Rotary vacuum-pump.



yN0. 846,933. Y PATENTED'MAR. l2, 1907.

' D. MGP. MOORE.

ROTARY VACUUM PUMP.

APPLIOATION I"ILEVD MAY 20, 1904.

10.846,933. PATENTED MAR. 12, 19o?. n. MOP. MooRE. ROTARY VACUUM PUMP.'

APPLICATION FILED MAY 20, 1904.

4 sanne-slum 2L ROTARY VACUUM PUMP. APPLIOATION FILED MAY zo, 1904.`

SHEETS-SHEET 4.

DANIEL, MCFARLAN MOORE,

TION OF NEW YORK.

anmTED srATEs PATENT -oEErcn OF NEWARK', NEW JERSEY, ASSIGNOR TO MOORE ELECTRICAL COMPANY, OF EW YORK, N.. Y., A CORPORA- ROTARY VACUUM-PUMP.

Specification of Letters Patent.

Patented March 12, 1907.

Application filed May 20,1904. vSerial No. 208,825.

sorb and dissipate the heat due to the opera- MoonE, a citizen of the United States, and a l resident of Newark, in the county of Essex and State of New Jersey,

, dress as'above, have invented certain new and useful Improvements 1n Rotary Vacuuml Pumps, of which the following is a specification.

My invention relates to air-pumps emwith post-ollice a'dtion of the apparatus.

In the accompanying drawings, Figure 1 is a side elevation of an apparatus embodying my invention. Fig. 2 is a plan of the same.

` Fig. 3 is an end elevation showing the first ployed for producing a vacuum; and the object of the invention .is to provide a simple and efficient apparatus embodying a rotary pump or pumps driven by mechanical power and suitable for use in producing a vacuum in i electric lamps of any type, more incandescent electric lamps of t e type departicularly j with inlet and outlet ports, as

vised by me and termed vacuum-tube;

lamps.

By my improved apparatus I provide a;

substitute for the ordinary mercury-pump and by mechanical power am enabled to attam a vacuumof much higher degree than it Y has hitherto been possible to obtain by the use of air-pumps of the mechanical type in i which pistons or vanes rotating have been used.

pump of the series and its principal connections. Fig. 4 is a similar view looking inthe same direction of the second or last pump of the series, the drive-shaft and the pipe cor nection being shown in section.

In carrying out my invention I propose to employ a rotary pump of any preferred construction, but preferably one of the revolvingvane type or one in which radial wings or valves work in an eccentric casing provided well lunderstood in the art. i,

In the drawings I show two pumps 1 2 and an inclosed liquid-tight tank 50. (Illustrated in Fig. 1 in vertical section.) The umps and tank are-` mounted on a suitable ase 3, upon which is also mounted, referably, the rotary driving-motor 4 of t 1e apmain driving-shaft 7 of the ap aratus, said My invention consists in certain improvei ments in the construction and manner of combining rotary vacuum-pumps, as herein- -after more particularly described and then 5 shaft 7 may obviously be the shaft for the specified in the claims.

not only vto immerse the pumps in an oilbath, but I also provide means for introducing oil to the inlet side of the pump, which oil operates as a seal and as` a lubrication for the rotary wings or valves.

In my improved apparatus the oil-bath, in which the pump and the incipal. connections thereof are immerse serves the very important purpose of sealing'the pump and its connectlons against the admission of the atmosphere through leaky bearings, loose stop-cocks, or other leaks and-assures an ef- -ficient operation of the same when revision is made for circulatin oil throng one or more of the pumps em Ioyed in the combination. The oil-bath a so serves the further im roved pur ose of lubricating the gearings an shaft or s afts emplo ed in rotating the pump and which for the by est resul-ts, should i' shaft 7 passing through an oil-tight stuffingbox 51 in the tank 5,0. The parts may be inclosed in a suitable frame 30, of cast-iron tubing, secured to the base 3. The driverotary member of the pump or pumps, but by preference is a counter-shaft geared to the ump-'shaft' through 'gears 6 and 5.4 T he iatter gear 5 is on the shaft' 7', which carrles the rotary member of both pumps and has the gear 5 secured to it between the pumps. The shaft 7 4is mounted within the tank 50 on suitable bearings secured to the vacuumpump casings, as shown at the meeting ends thereof. give strength to the drive members o the apparatus, as well as to balance up the shaftmg andv to give smoothness of operation. All the mechanism with the exceptionof the motor 4 is inclosed, yas shown, in the casing 50, which holds oilto a height sufficient to immerse the pump or pumps and the dr1v1ng connections. For an oilv I prefer to use a heavy mineral oil-suc'h, for instance, as cylinder stock-oil. e

1 indicates the high-vacuum pump of the ycombination or that which is connected di-v which a sutable quantity of oil has been pre-` rectly tothe pipe or tube 60, joined to the reviously introduced. The course of the' oil ceptaclein which the vacuum is to be produring operation of the pump is through the duced or maintained, while 2 is the low-.vacucylinder 8, thence through port 9 into pump termination of the system and is joined to with air out at port 1() and through outletthe outlet 19, from which the air exhausted port 12. The oil falls to the bottom of the from the receptacle escapes. receptacle 11 and is trapped there, While the s Betweenthe pipe 60 and the inlet 9 .for air passing out through the opening 13 is '.o pu1np'1 is interposed the cylinder 8- which is carriedA by pipe 14 to thev pump 2, then 75 made, as shown, of a largersize than the through an inlet-port 15 of the latter and pipe 60 and connections' in order that it may through said pump to the outlet 16 through act as ai'reservoir. Outlet 10l of the pump is the back-pressure valve 17, opening upward coupled to acylinder or rece tacle 11 of and into the cylinder 18,where any-entrained l5 suitable construction to' provi e anoil-'trap oil is trapped, as in the cylinder 11. 'The air. 8o for oil passing with the air through the outpasses onirom c linder` 18 to the outlet 19, l let 10. For this purpose the receptacle 11, which is the out et-port of the series of exwhich is preferably of glass, may be provided hausting devices and which, as already witha pipe 127 forming a continuation of the stated, opens into the tank F0 in order that 2O. outlet 10 and rising in the tube 11 to a suite any oil escaping may be' recovered. The 85 able height, Where itis provided With an outoil trapped in cylinder 1 1 is permitted to ass let-port 12. The oil collecting in the botback'to port 9, the ilow being regulated3 by tom of the cylinder or receptacle 11 is revalve 21. The oil thus circulated in Ythe turned by a pipe 20 to the inlet port or pipe pump 1 helps'to draw the air through said v 9, the iow being regulated, if desired, by a pump by mixing with it, the two` being sepa- 9o valve 21. The air which passes through the rated incylinder or recetacle 11, in which ort '12 into the cylinder 11 is .delivered circulation of the air is ba ed or delayed and through lthe port 13 in a ipe 13, which enthe oil permitted to drop to the bottom of ters the top of the receptaclle V11, and through the cylinder. 3Q said pipe 13 the air passes by a pipe 14, as 1n starting the pump or when drawing 95 shown, to theinlet port or pipe 15 ot the seclarge quantities or air through it the oil in ond member or pump 2 of the series. The lcylinder 11 will foam, due to the vacuum outlet 16 of the latter may be connected to a produced by pump 2, and same will pass receptacle 18 of similar construction to the ortend to pass over into the pump 2, but

um pump or the one'whose outlet forms the.. l, the blades of which force the oil mingled 7o,

5S receptacle 11. For this purpose the outlet will there be dropped in cylinder 18. This 10o may terminate in a pipe 32, risingin the reoil may be returned to cylinder 11, when deceptacle 18 andprpvided with a ort 32', sired, through the pipe 22 by openin the this construction "serving to provide at the valve 23,which,hoWev-er,must be close durbottom ot' the' cylinder 18 a trap .for oil ing normal operation.

40 which may pass from the rst to the second vAll pipe and other joints, especially those 1o 5 member of the series. From the cylinder 1.8 above the oil-bath, must be made absolutely the air passes through the port 33 in a pi e air-tight by soldering or other eilicient means. 33, entering the cylinder, and finally tot e By maintaining a column of oil in the cyloutlet 19, which, as shown, is suitably .arinder 11 at a level above the outlet-port 12"- 4S ranged to deliver into the tank 50, so that as, for instance, at the level indicated by the I 10- any escaping oil will be returned thereto. horizontal dotted line 7 -said column will From the trap at the bottom of cylinder 18a operate as a back-pressure valve to effectupipe 22 leads to the cylinder 11. In said ally prevent the return of air forced'through pipe is a stop-cock 23., which is closed durthe outlet of the first pump of the series 5 ing normal operation. When, however, the thereof, giving a still more effective action to I I 5 pump stops, the opening of this valve or stopthe apparatus. cock 23 will errnit the oil trapped in 18 to re- What I claim bas'my invention is turn by bac pressure to the cylinder 11 and l '1- The combination with a pair of rotary back to the pump 1, as already described, -r pumps working in series in an oil-bath, of an through pipe 20. oil-collecting kcylinder or receptacle, a. pipe 120' In the outlet 16 of the pump 2 asuitable opening into said receptacle and forming a back-pressure valve 17 is located for the purcontinuation of the outlet for the first pump pose of' stopping the backflow ot air through of the series, and a second pipe connecting the pump 2 and causing back circulation of the air-space of said rece tacle with the inlet oil to take placethrough pipe 22, as just deg for the second ump of t e series. 125 scribed, when the valve 23 is open. When 2. rilhe com ination substantially as de the pump is started, a suitablepamount of oil scribed, of two rota ry pumps working in seis introduced in the pump 1 through the pipe ries in an oil-bath, an oil-collecting chamber 20 by opening the valve 21 and allowing it to l having two connections, one leading from 65 flow from the bottom of the cylinder 11 into l the outlet of the first pump of the series and 130 pumps workin in tandem or series, of an oi trap connecte with the outlet of .the series,

a return pipe or connection for returning the oil to the inlet of the series, a shut-off valve in said return-pi e and a back-pressure valve between the out et of the series and the point of connection of said return-pipe.

4. The combination with two rotary umps connected up in series, of an intermeiate chamber adapted to collect oil, a pipe leadin into said, chamber above thev bottom thereo and joined to the outlet of the first A pump of the series, and a second pipe or connectlon leadin f from said 'chamber above the level of the oi and joined tothe inlet of the second pump of the series.

- 5. The combination with a pair of rotary vacuumumps, of an oilbath, a cylinder or receptac e 11, a pige -12 forming a continuation of the outlet om the first pump of the series and rising in said c linder, said pi e j being provided with an out et-port above t e level of the oil collecting in the bottom of said cylinder, a return-pipe for returning the oil to the inlet-port of the first pum a pipe 13 connected with the air-space in t e rece tacle 11 and joined tto the inlet-port of t e second member or pumpz a receptacle 18 in which terminates a pi e joined to the outlet of the second um. o the series, and means for returning t e oi Atrapped in said receptacle to the cylinder or receptacle 11.`

Signed at New York, in the county of New York and State of New York, this 18th day of May, A. D. 1904. v v

C. F. TISCHNR, Jr., Zo ANNA TALLHAN. 

